Instituto de Materiais (iMATUS)

Permanent URI for this collectionhttps://hdl.handle.net/10347/34304

O Instituto de Materiais (iMATUS) é un centro de investigación de excelencia que desenvolve ciencia de fronteira sobre novos materiais e as súas aplicacións en saúde, medio ambiente, enerxía e innovación industrial. A investigación de iMATUS achega solucións a grandes retos sociais e contribúe ao desenvolvemento económico de Galicia, achegando tecnoloxía e I+D colaborativa para facer máis competitiva a súa industria. iMATUS aspira a ser un centro de investigación de referencia internacional no campo dos materiais. A misión do Instituto é facer ciencia multidisciplinar de excelencia e ter un impacto científico e socioeconómico en ciencia e tecnoloxía de materiais, apoiándose no ecosistema de I+D+i con que conta Galicia.

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Accuracy of cytological methods in early detection of oral squamous cell carcinoma and potentially malignant disorders: A systematic review and meta-analysis
(Wiley, 2025-08) Tayebi Hillali, Hoda; Lorenzo Pouso, Alejandro Ismael; Marichalar Mendía, Xabier; Gándara Vila, Pilar; Reboiras López, Dolores; Blanco Carrión, Andrés; Coppini, Martina; Alberto Caponio, Vito Carlo; Pérez-Sayáns García, Mario; Universidade de Santiago de Compostela. Departamento de Cirurxía e Especialidades Médico-Cirúrxicas; Universidade de Santiago de Compostela. Instituto de Materiais (iMATUS)
Introduction: Oral squamous cell carcinoma (OSCC) carries significant global mortality rates. Brush cytology presents a potential adjunctive tool for early detection and monitoring of OSCC and oral potentially malignant disorders (OPMDs). This study aims to systematically evaluate the diagnostic accuracy of cytology for detecting OSCC and OPMDs compared to histopathology as the reference standard. We conducted a systematic review and meta-analysis following PRISMA-DTA guidelines. Material and methods: We searched PubMed, Embase, Scopus, Cochrane Library, and Web of Science from inception to January 2023 (updated in March 2025). Eligible studies included cohort studies evaluating cytology versus histopathological diagnosis. Two reviewers independently screened studies, extracted data, and assessed risk of bias using QUADAS-2. We used the Hierarchical Summary Receiver Operating Characteristic model for meta-analysis. Results: Of 2603 identified studies, 53 met inclusion criteria, comprising 13,249 patients. Cytology demonstrated a pooled sensitivity of 0.914 (95% CI: 0.878-0.941) and specificity of 0.960 (95% CI: 0.937-0.975). The diagnostic odds ratio was 137.502 (95% CI: 79.733-237.127), with a positive likelihood ratio of 11.970 (95% CI: 9.005-15.912) and negative likelihood ratio of 0.096 (95% CI: 0.059-0.158). Subgroup analysis showed improved performance when exfoliative cytology was combined with DNA analysis or when using a metal spatula. Both conventional and liquid-based cytology were effective, with the latter showing modest advantages. Heterogeneity was substantial across studies (I2 = 86.26%). Conclusion: Cytology demonstrates good diagnostic accuracy for detecting OSCC and OPMDs and may serve as a valuable adjunctive screening tool. However, it does not replace histopathological examination as the diagnostic gold standard. Further research should focus on standardizing collection techniques and interpretation criteria. Registration: PROSPERO CRD42023438610.
Oxygen-generating and antibacterial xanthan gum/PLA aerogels loaded with dexamethasone for potential wound healing
(Elsevier, 2025-04-19) Hozjan, Nika Atelšek; Horvat, Gabrijela; Finšgar, MMatjaž; Iglesias-Mejuto, Ana; Ardao Palacios, Inés; García González, Carlos A.; Knez, Zeljko A.; Novak, Zoran; Universidade de Santiago de Compostela. Departamento de Farmacoloxía, Farmacia e Tecnoloxía Farmacéutica; Universidade de Santiago de Compostela. Instituto de Materiais (iMATUS)
Chronic wounds do not heal within a reasonable time frame due to hypoxia and bacterial inflammation, creating an urgent need for advanced biomaterials to address these challenges. In this study, oxygen-generating, antibacterial xanthan gum-polylactic acid (XA/PLA) aerogels loaded with dexamethasone were developed for the first time for potential wound healing applications. The aerogels contained sodium percarbonate and calcium peroxide as oxygen-releasing agents, providing sustained oxygen release for up to 48 h. The aerogels had a highly porous structure with a high specific surface area (up to 396 ± 8 m2/g) and revealed high liquid absorption capacity in simulated body fluid, absorbing up to 67 times their original weight and remaining stable for 72 h. The in vitro release tests showed controlled profiles of dexamethasone over 24 h. The antibacterial tests demonstrated strong antibacterial activity against Escherichia coli (an up to 15.92 mm inhibition zone diameter) and Staphylococcus aureus (up to a 31.07 mm inhibition zone diameter). The in vitro biocompatibility assays revealed good cytocompatibility with mouse fibroblast cells (NIH/3T3), with a cell viability of >90%. Hemocompatibility tests showed no hemolytic activity with human blood (lysis rate <2%). Overall, these results emphasise the versatility of the XA/PLA aerogels and their potential for the treatment of chronic wounds.
In Vitro Structural and Functional Studies of a Novel Cupredoxin, FtrB, from Brucella abortus 2308
(American Chemical Society, 2025-03-22) Kerkan, Alexa; Santisteban Veiga, Andrea; Banerjee, Sambuddha; Universidade de Santiago de Compostela. Departamento de Física Aplicada; Universidade de Santiago de Compostela. Instituto de Materiais (iMATUS)
FtrABCD is a four-component iron transporter found in several Gram-negative bacteria. Previous data confirm that FtrABCD can only utilize Fe2+ and the inner membrane permease, FtrC, from this system, like its eukaryotic homologue, Ftr1p, is predicted to utilize the free energy released during Fe2+ oxidation for the transport. Periplasmic FtrB from this system is coancestral with known copper oxidases, and the conserved D118 and H121 are predicted to bind to Cu2+, forming an active enzyme. In this work, we report structural data for recombinant wild-type and D118A and H121A mutants from Brucella abortus 2308 which confirm a β-sheet-rich structure which is distinct from known cupredoxins. Calorimetric studies on the wild-type protein show μM affinities for Cu2+ and an Fe2+ mimic (Mn2+), which facilitate the formation of the active enzyme and the enzyme-substrate complex, respectively. In contrast, the D118A mutant failed to bind Cu2+. Finally, the electrochemical data reported here revealed biologically accessible reduction potentials for the Cu2+ ion in the active enzyme which also showed a pseudozero-order rate of Fe2+ oxidation at pH 6.5 and could oxidize Fe2+ 3.5-times faster than its rate of autoxidation. Taken together, this report provides experimental data that support structural and functional predictions of FtrB under in vitro conditions.
Disulfiram-loaded electrospun fibers with antimicrobial and antitumoral properties for glioblastoma treatment
(Elsevier, 2025-03-12) González Prada, Iago; Barcelos Ribeiro, Arthur; Dion, Marine; Magariños Ferro, Beatriz; Lapoujade, Clémentine; Rousseau, Audrey; Concheiro Nine, Ángel Joaquín; Garcion, Emmanuel; Álvarez Lorenzo, Carmen; Universidade de Santiago de Compostela. Departamento de Farmacoloxía, Farmacia e Tecnoloxía Farmacéutica; Universidade de Santiago de Compostela. Departamento de Microbioloxía e Parasitoloxía; Universidade de Santiago de Compostela. Instituto de Materiais (iMATUS)
Glioblastoma (GB) is a malignant brain tumor with low survival rates and a high recurrence ratio due to limited therapeutic arsenal. The repurposed drug disulfiram (DSF), approved for alcoholism treatment, shows promising anticancer and antimicrobial activity, but its poor biopharmaceutical profile hinders its clinical use. This work aimed to develop DSF-loaded silk fibroin (SF) electrospun fibers for controlled release in the postsurgical resection cavity. Incorporating hydroxypropyl-β-cyclodextrin (HPβCD), which formed inclusion complexes with DSF, enhanced drug release rate and antimicrobial activity (>3 logCFUs reduction) against Staphylococcus aureus and Pseudomonas aeruginosa. Addition of CuCl2 enabled in situ formation of Cu(DDC)2 complexes, further boosting antimicrobial and in vitro antitumoral effects of the nanofibers (≤ 500 nm) while maintaining adequate mechanical properties. Selective toxicity of DSF and DSF-loaded fibers against glioblastoma cells, while sparing against astrocytes, highlights the potential of the nanofibers for targeted brain cancer therapy. Increased potency of DSF at low concentrations when combined with SF fibers, HPβCD and copper was remarkable. Thus, DSF delivery and bioavailability can be significantly optimized through electrospun nanofibers, which may also allow for more precise dosing. Combination with radiotherapy was also explored to assess the translational potential of DSF as part of a combination therapy regimen for glioblastoma. In vivo studies in a rat model simulating GB surgery confirmed the safety of selected formulations in healthy brain tissue. However, findings suggest that DSF-loaded fibers alone may be insufficient for complete tumor eradication, indicating the need for combination with existing therapies to target residual tumor cells effectively.
A fast and automated approach for urban CFD simulations: validation with meteorological predictions and its application to drone flights
(Elsevier, 2025-12) Suárez Vázquez, Marcos; Varela Ballesta, Sylvana; Otero Cacho, Alberto; Pérez Muñuzuri, Alberto; Mira Pérez, Jorge; Universidade de Santiago de Compostela. Departamento de Física Aplicada; Universidade de Santiago de Compostela. Instituto de Materiais (iMATUS); Universidade de Santiago de Compostela. Departamento de Física de Partículas
In past years, several studies have proposed new methods and applications for urban wind simulations, including geometry reconstruction from urban data sources or improved boundary condition definition. In this article, we present a fast and automated methodology for reconstructing airflows within urban environments using LiDAR and cadastral data coupled with Computational Fluid Dynamics (CFD) simulations. Our approach integrates meteorological predictions with computational techniques to simulate the complex interactions between wind currents, buildings, vegetation, water zones and terrain morphology within urban environments. Accurate boundary conditions based on meteorological predictions are introduced into a coupled methodology that directly creates the terrain shape inside the simulation environment, simplifying the geometry creation process, which is one of the most prevalent problems in CFD urban simulations. The simulation results are confronted against ground-truth real data obtained from a meteorological station, showing strong agreement with the outcomes generated by the proposed CFD model, with a concordance correlation coefficient up to ρ and ρ c c =0.985 for the wind direction =0.853 for the wind speed. The results from these simulations are then used for validating a wind tunnel approach that mimics the interaction between a moving drone and the extracted wind currents, demonstrating a great improvement in computation times when compared to the most straightforward approach that consists in embedding the drone within the full urban landscape. This research contributes to the advancement of urban CFD modeling, and it has significant implications for various applications, providing valuable insights for urban development.
On the physical foundations of topological thermoelectricity and its improvement
(Elsevier, 2026-01-22) Baldomir Fernández, Daniel; Failde, Daniel; Universidade de Santiago de Compostela. Departamento de Física Aplicada; Universidade de Santiago de Compostela. Instituto de Materiais (iMATUS)
Thermoelectricity has extraordinary scientific and technological interest due to its ability to utilize heat losses through the Seebeck effect and Peltier cooling in circuits. However, the efficiency of thermoelectric materials remains relatively low, making them economically viable in fewer cases than desired. A promising possibility lies in the best thermoelectric materials at room temperature, specifically the well-known tetradymite-type structures, primarily compounds based on . These materials are characterized as topological insulators, allowing for the introduction of new physical perspectives. Therefore, it is reasonable to closely investigate the interplay between topology and thermoelectricity in these systems, with the aim of elucidating the underlying physical mechanisms. We show that, near the surface–bulk interface, the electrodynamics of axions coupled to massless fermions, Thouless pump currents, the chiral anomaly, and topological mass are intimately interconnected in a way that enables the mutual conversion of heat and electrical energy. That gives rise to a thermoelectric effect whose efficiency can be enhanced by integer multiples. We extend this study to heterostructures of topological insulators and topological superconductors. These phases are topologically complementary and may use the proximity effect to share topological quantum numbers. This offers a pathway to enhance topological thermoelectricity.
Biomimetic core-shell breast cancer models using alginate, gelatin, and collagen I: simulating the tumor matrix for drug evaluation
(Elsevier, 2026-01) Gato Díaz, Uxía; Castro Alves, Lisandra de; Concheiro Nine, Ángel Joaquín; Piñeiro Redondo, Yolanda; Álvarez Lorenzo, Carmen; Blanco Fernández, Bárbara; Rivas Rey, José; Universidade de Santiago de Compostela. Instituto de Materiais (iMATUS); Universidade de Santiago de Compostela. Departamento de Física Aplicada; Universidade de Santiago de Compostela. Departamento de Farmacoloxía, Farmacia e Tecnoloxía Farmacéutica
Breast cancer remains among the most prevalent cancers in women worldwide. During tumor development, the extracellular matrix is altered to support tumor progression and therapy resistance. Therefore, there is a need to develop breast cancer models that replicate the complex tumor extracellular matrix to accurately mimic the mechanisms by which it influences drug resistance and cancer cell malignancy. In this study, we fabricated an innovative breast cancer 3D in vitro model consisting of core-shell hydrogel beads from alginate, gelatin, and collagen I by extrusion through a coaxial needle. Breast cancer cells proliferated in the core of all prototypes designed, forming spheroids and cell aggregates with a high resistance to doxorubicin. The addition of Collagen I to the developed model enabled the upregulation of malignancy markers (Col1A1, Ki67, FOXC2, SNAI1, NFKB1, WWTR1), invasion markers (WASL, ACTA1, MYO1E, TPM4, PODXL, ITGA2, ITGA5, MENA, EGFR, CDC42), and drug resistance markers (ABCG2, CYP1A1, BAX, HSP90AA1) occurring in vivo. The developed 3D in vitro model can clarify the contribution of the extracellular matrix to the tumor outcome and drug efficacy by replicating some key characteristics of breast tumors, establishing a novel tool for chemotherapeutic agents and drug screening.
Engineering of green sterilization technology to obtain biocompatible aerogels: Supercritical CO2 versus ethylene oxide and gamma radiation
(Elsevier, 2026-01-02) Carracedo Pérez, María; Boccia, Antonella Caterina; Ardao Palacios, Inés; Passos, Cláudia Pereira; Santos Rosales, Víctor; Santos Torres, Beatriz; Bernardo, Fábio Gabriel Pereira; Blanco Vales, María; Magariños Ferro, Beatriz; García González, Carlos A.; Universidade de Santiago de Compostela. Departamento de Microbioloxía e Parasitoloxía; Universidade de Santiago de Compostela. Instituto de Materiais (iMATUS); Universidade de Santiago de Compostela. Centro de Investigación en Medicina Molecular e Enfermidades Crónicas (CiMUS); Universidade de Santiago de Compostela. Instituto de Investigación do Medio Acuático para Unha Saúde Global (iARCUS)
The growing relevance of aerogels in biomedicine demands the choice of compatible sterilization techniques with these materials. Conventional methods, such as ethylene oxide (EO) and gamma radiation (γ-rays) sterilization, have significant drawbacks while facing important environmental restrictions. In this study, supercritical CO2 (scCO2) sterilization is tested for polysaccharide (starch and alginate) aerogels as an eco-friendly alternative to conventional procedures. Three post-processing treatments under different CO2 exposure regimes (static, dynamic and combined) and in the presence of H2O2 as additive were developed and assessed to reach sterility assurance levels (SAL) below 10−6. After sterilization, a vacuum treatment was implemented to ensure a low residual presence of H2O2 in the aerogels so that the material biocompatibility was not compromised according to in vitro cell tests with fibroblasts. The residual adsorbed H2O2 was quantified for the first time in aerogels by nuclear magnetic resonance spectroscopy. The effects of the supercritical sterilization treatments on the textural and chemical properties of the aerogels were evaluated and compared to those treated with EO and γ-rays. Results highlight the unique efficiency of scCO2 sterilization as a post-processing method that preserves the aerogel structure while offering an eco-sustainable potential for producing sterile and biocompatible materials.
Surface-engineered gold nanorods for targeted delivery of PD-L1 siRNA and cancer chemo-phototherapy
(Royal Society of Chemistry, 2025-10-09) Arellano, Lilia; Villar Álvarez, Eva; Cambón Freire, Adriana; Costa Santos, Alba; Pardo Montero, Alberto; Topete Camacho, Antonio; Barbosa Fernández, Silvia; Taboada Antelo, Pablo; Universidade de Santiago de Compostela. Departamento de Física de Partículas; Universidade de Santiago de Compostela. Instituto de Materiais (iMATUS)
Nowadays, cancer remains a global leading cause of death, with therapeutic advances often hindered by drug resistance and adverse side effects. The integration of nanotechnology with immunotherapy has emerged as a promising approach to enhance specificity and efficacy of oncological treatments. A key immunotherapeutic target is the so-called programmed death-ligand 1 (PD-L1), a protein that enables tumors to evade immune surveillance and increase their chemotherapy resistance. Interestingly, RNA interference using small interfering RNA (siRNA) targeting PD-L1, has shown potential in reactivating anti-cancer immune responses. However, efficient delivery of siRNA still faces challenges in terms of stability, cellular uptake, and/or targeted release. In this study, we developed a multifunctional theranostic nanoplatform based on gold nanorods (GNRs) surface-engineered through a layer-by-layer assembly with poly(styrene sulfonate), poly(L-lysine), and hyaluronic acid, to provide enhanced stability and active targeting towards CD44 receptors overexpressed in cancer cells. Within the polymeric multilayers PD-L1 siRNA, doxorubicin and indocyanine green were loaded for multimodal therapeutic activity. The anti-tumor effect, siRNA transfection efficiency and cell death mechanism of the nanoplatform was evaluated on HeLa cells expressing PD-L1 and CD44 and Balb/3T3 fibroblasts. The surface-engineered GNRs-based nanosystem efficiently transfected PD-L1 siRNA and allowed subsequent application of multimodal chemo-, photodynamic and photothermal therapy with enhanced cytotoxicity.
Surface-modified iron oxide nanoprobes in biomedical scaffolds
(Royal Society of Chemistry, 2025-11-17) González Gómez, Manuel Antonio; Arnosa Prieto, Ángela; García Acevedo, Pelayo; Díaz Rodríguez, Patricia; Castro Alves, Lisandra de; Piñeiro Redondo, Yolanda; Rivas Rey, José; Universidade de Santiago de Compostela. Instituto de Materiais (iMATUS); Universidade de Santiago de Compostela. Departamento de Física Aplicada
Magnetic (PU) scaffolds incorporating superparamagnetic iron oxide nanoparticles (SPIONs) offer a promising platform for localized cancer therapy. By enhancing the functional performance of these scaffolds through surface modification of iron oxide nanoprobes, their biomedical utility—particularly in targeted therapeutic applications—can be significantly improved. In this study, we report the synthesis and characterization of magnetite nanoparticles (Fe3O4 NPs) functionalized with biocompatible coatings—citrate, polyethylene glycol (PEG), oleic acid (OA), and aluminum hydroxide (Al(OH)3)—and their integration into porous PU scaffolds via a salt-leaching/phase-inversion method. Among all tested formulations, SPIONs@Al(OH) demonstrated superior colloidal stability, magnetic responsiveness, and cytocompatibility. When embedded in PU scaffolds, these magnetic nanocomposites exhibited optimal mesoporosity, homogeneous nanoparticle distribution, and efficient magnetic hyperthermia performance under clinically relevant alternating magnetic fields. This work highlights the synergistic potential of material design and surface engineering in developing next-generation implantable platforms for targeted oncological treatment.
Impact of Electronic Nicotine Delivery Systems on Oral Mucosa: A Cytopathological and Molecular Study
(Wiley, 2026-03) Pérez Jardón, Alba; Chamorro Petronacci, Cintia Micaela; Reboiras López, María Dolores; E Silva, Fábio França Vieira; Padín Iruegas, María Elena; Pérez-Sayáns García, Mario; Almeida, Janete Días; Universidade de Santiago de Compostela. Instituto de Materiais (iMATUS)
Background: The packaging and marketing of electronic cigarettes (e-cigs) often target younger demographics. This study aimed to evaluate gene expression in e-cig users through exfoliative cytology. Methods: Samples were collected from 17 e-cig users and 10 nonsmokers as controls. Clinical data included age, gender, heart rate, oximetry, capillary blood glucose, carbon monoxide levels, sialometry, alcohol-related risk scores, alcohol consumption, and e-cig use parameters. Smears from the left tongue edge were obtained using a Rovers Orcellex Brush. The Papanicolaou method assessed epithelial maturation and cytological features, categorized from normal to conclusive for malignancy. Cellular composition, inflammation, microbial presence, and atypia were evaluated using a semiquantitative scoring system. Gene expression (p16, IL1-beta, CXCL8, TNF, and KRT13) was analyzed by RT-PCR. Statistical comparisons used the Mann-Whitney test, and correlations were assessed via Spearman's test (p ≤ 0.05). Results: Fruit flavors were the most preferred. Some users were former smokers (average abstention: 3.15 months). Bacterial colonies were more prevalent in the e-cig group (64.7% vs. 20%, p = 0.085), mucus and inflammatory changes were found exclusively in e-cig users (p = 0.062). No significant differences were found in the Papanicolaou classification by gender (p = 0.904). Gene expression analysis showed a differential expression of p16 and TNF between the groups. Significant correlations were found between carbon monoxide and p16 expression (r = -0.41, p = 0.02), vaping sessions per day and p16 expression (r = -0.37, p = 0.02), and daily alcohol dose and TNF expression (r = -0.42, p = 0.04). Conclusion: E-cigarette use may induce early molecular and cytological changes in the oral mucosa, affecting inflammation, immunity, and epithelial differentiation.
Engineering aerogel particles as next-generation drug delivery systems: a comprehensive review of recent advances
(Elsevier, 2026) Gomes, Susana M.; Illanes Bordomás, Carlos; García González, Carlos A.; Akgün, Işık Sen; Universidade de Santiago de Compostela. Instituto de Materiais (iMATUS); Universidade de Santiago de Compostela. Departamento de Farmacoloxía, Farmacia e Tecnoloxía Farmacéutica
Aerogels, defined as low-density solid materials with high porosities, open pore structures, and high specific surface areas, have shown increasing interest among the scientific and industrial communities. The engineering of aerogels in the form of spherical particles has been well documented for several applications and recent studies have highlighted the promising potential of use them as drug delivery systems. Therefore, this review article consolidates the recent progress on aerogel particle technology by providing a comprehensive and focused synthesis of the state-of-the-art of aerogel particle design specifically intended to enhance biocompatibility, stability, and targeted drug delivery. The engineering technologies herein presented, based on droplets production and on the milling technology, are critically discussed, highlighting critical aspects used to control their features. Moreover, surface modification and coating techniques are critically examined as tools to enhance biocompatibility, colloidal stability, and targeted delivery. Then, key results in the diverse biomedical applications, namely for oral, skin and pulmonary drug delivery, were discussed. In oral delivery, their capacity to improve drug loading and enable sustained release is emphasized. In skin delivery, aerogels show potential to enhance dermal permeation and provide a sustained release. For pulmonary administration, their low density and aerodynamic properties make them ideal for deep lung deposition. By bridging particle engineering with therapeutic functionality, this review highlights the unique features and advantages of aerogel particles to become the next-generation aerogel-based therapeutic systems. Finally, the current challenges to be addressed and future trends are identified.
Nail tattooing: a novel and minimally invasive technique for enhancing drug penetration through the nail
(Springer, 2026-03-26) Seoane Viaño, Iria; Bendicho Lavilla, Carlos; Díaz Tomé, Victoria; Seoane Viaño, Iria; Monte Vidal, Vinicius de; Otero Espinar, Francisco Javier; Universidade de Santiago de Compostela. Instituto de Materiais (iMATUS)
Onychomycosis, a prevalent fungal infection, and psoriasis, a chronic immune disorder affecting the nail plate, present therapeutic challenges due to the limited efficacy of current treatments, often leading to prolonged therapy and a high relapse rate. The highly cross-linked keratin network of the nail plate acts as a barrier, impeding effective drug delivery. This pioneering study explores a novel approach using a tattoo device to enhance drug penetration through the nail. Ciclopirox olamine and clobetasol lacquers were selected as the model formulations. Drug permeation tests conducted on non-treated, filed (mechanically abraded), and tattooed nails demonstrated significantly higher drug permeation in tattooed nails, suggesting the potential of this delivery method. Nail tattooing offers a simple method to enhance topical therapy, allowing treatment initiation in the clinic and continuation at home.
Ligand-Driven Optimization of Iron Oxide Nanoprobes forIn Vivo MRI Enhancement at Ultra-High Field
(Wiley, 2026-02-03) García Acevedo, Pelayo; Alonso Alonso, María Luz; Ortega Espina, Sara; Bañobre López, Manuel; Piñeiro Redondo, Yolanda; Iglesias Rey, Ramón; Rivas Rey, José; Universidade de Santiago de Compostela. Departamento de Física Aplicada; Universidade de Santiago de Compostela. Instituto de Materiais (iMATUS)
Ultra-high-field magnetic resonance imaging (UHF-MRI, B0 > 7 T) combined with contrast enhancement (CE-MRI) offersunmatched spatial resolution, but high-field effects limit the performance of negative contrast agents. Here, we report a ligand-driven strategy to modulate the T2 relaxivity (r2 ) of monodisperse 12 nm iron oxide-based contrast agents synthesized by thermaldecomposition. Five surface chemistries–polyacrylic acid (PAA), poly(isobutylene-alt-maleic anhydride) (PMA), poly(maleicanhydride-alt-1-octadecene) (PMAO), citric acid (CA), and silica (SiO2 )─ were investigated under physiological conditions andin vivo using relaxometry (1.4 T), clinical (3 T), and UHF (9.4 T) MRI, achieving up to a 333 mm−1 s−1 increase in r2 . CA-coated T2contrast agents exhibited record-high r2 values (522 mm−1 s−1 at 3 T; 381 mm−1 s−1 at 9.4 T) in spherical iron oxide MNPs withinthe superparamagnetic size range (d < 20 nm). Correlations of r2 with hydrodynamic size, ζ-potential, and coating thicknessrevealed that ligand chemistry–specifically hydrophilicity and anionic surface charge–dominates over physical shell dimensionsin governing water accessibility and magnetic dephasing. This scalable ligand-exchange strategy enables precise T2 tuning at UHF,with phantom results reliably predicting in vivo UHF-MRI performance in rat brain models, advancing the design of neuroimaging nanoprobes.
Multifunctional hybrid chitosan/κ-carrageenan sponges integrating engineered SBA-15@Fe3O4 composites and nano-hydroxyapatite for bone tissue engineering
(Elsevier, 2026-04) Vargas Osorio, Zulema; García Acevedo, Pelayo; Piñeiro Redondo, Yolanda; Michálek, Martin; Luzardo Álvarez, Asteria María; Otero Espinar, Francisco Javier; Boccaccini, Aldo Roberto; Rivas Rey, José; Universidade de Santiago de Compostela. Departamento de Física Aplicada; Universidade de Santiago de Compostela. Instituto de Materiais (iMATUS)
Conventional therapies often struggle to overcome key challenges associated with bone tissue disorders that demand advanced and sustained therapy solutions. This underscores the urgent need for multifunctional platforms that combine diagnostic and therapeutic functions with bioactive, degradable, and mechanically robust components. Herein, BDDE-crosslinked chitosan/κ-carrageenan sponges incorporating engineered SBA-15/Fe3O4 composites and nano-sized hydroxyapatite (nHAp) crystals were fabricated and investigated. The resulting hybrid sponges exhibited full shape recovery after mechanical compression under wet conditions and a remarkable absorption capacity without compromising their porous structure, attributed to strong structural integrity. The encapsulated SBA-15/Fe3O4 particles imparted hierarchical porosity and significant surface roughness, enabling high loading (≥150 mg/g) of simvastatin, a drug with potential to enhance bone regeneration, as well as its controlled release over extended periods ≥30 days. Additionally, these engineered composites conferred magnetic hyperthermia functionality, achieving specific absorption rates (SAR) ranging from 1.82 W·g−1 to 22.44 W·g−1 when applied a magnetic field of 28 mT at different kHz, providing them with the ability to modulate the heat response. The incorporation of nHAp into the sponge formulation enhanced both their bioactivity when tested in simulated physiological media, and cell adhesion and proliferation, as confirmed by in vitro direct and indirect contact assays. Cytocompatibility assessments using mouse macrophage (RAW 264.7), human osteosarcoma (MG-63), and preosteoblast (MC3T3-E1) cell lines demonstrated ≥80% viability across all models, revealing the highest proliferation in direct contact. These synergistic and versatile sponges hold promise for applications in bone tissue engineering.
Assessing the best hour to start the day: an appraisal of seasonal daylight saving time
(The Royal Society, 2025-03-19) Martín Olalla, José María; Mira Pérez, Jorge; Universidade de Santiago de Compostela. Departamento de Física Aplicada; Universidade de Santiago de Compostela. Instituto de Materiais (iMATUS)
We provide an evidence-based position on the seasonal regulation of clocks daylight saving time (DST) that challenges position papers by sleep associations against the practice. We review the acute, short-term impact and the chronic, long-term impact of DST in the context of the changing ambient light conditions that characterize seasons at Extratropical latitudes. We highlight the association between DST, human physiology (photoreceptive mechanisms) and human daily life. We offer a perspective on the possible scenarios should clock regulations be abandoned.
Influence of Abutment Shape on Implant Marginal Bone Remodeling: A Double-Blind, Randomized 24-Month Clinical Study
(Wiley, 2025-12-30) Seijas Naya, Flavio; Bernabeu Mira, Juan C.; Pérez Jardón, Alba; Conde Amboage, Mercedes; Peñarrocha Oltra, David; Camacho Alonso, Fabio; Pérez-Sayáns García, Mario; Universidade de Santiago de Compostela. Departamento de Estatística, Análise Matemática e Optimización; Universidade de Santiago de Compostela. Instituto de Materiais (iMATUS); Universidade de Santiago de Compostela. Departamento de Cirurxía e Especialidades Médico-Cirúrxicas
Objective This study follows a 2-year evaluation to verify marginal bone remodeling (MBR) trends associated with different abutment designs. Methods A balanced, randomised, double-blind clinical trial with two parallel experimental arms. 68 implants were placed in 9 men and 12 women, 48.5% using the straight abutment and 51.5% the concave abutment. The primary variable was peri-implant tissue stability, measured by marginal bone loss (MBL) or gain (MBG) through digital radiology. Mixed linear regression models and Additive Generalized Additive Models were constructed to estimate MBR, simultaneously considering the variables abutment height, group, and time. Results At 24 months, linear mixed-effects regression models revealed that the concave abutment group exhibited significantly less MBL than the straight abutment group across mesial, distal, and average measurements (p = 0.006–0.026). Significant interactions between abutment type and time at 8 weeks and 6 months suggest early and sustained benefits of the concave design. At 24 months, this effect remained significant except in the mesial model (p = 0.072). Abutment height was positively associated with MBL, particularly in the straight group; however, in the concave group, greater height mitigated bone loss (p < 0.01). Conclusion Concave abutments demonstrated a potential advantage in reducing early marginal bone loss and promoting mid-term bone stability compared to straight abutments. Their design may enhance soft tissue adaptation, contributing to improved peri-implant bone preservation. While increased abutment height showed a protective effect in the concave group, these findings require confirmation. Further long-term studies are warranted to validate these results and clarify their clinical relevance.
Microfluidics-Driven Manufacturing and Multiscale Analytical Characterization of Nanoparticle-Vesicle Hybrids
(Wiley, 2025-02-07) Cardellini, Jacopo; González Gómez, Manuel Antonio; Rivas Rey, José; Arosio, Paolo; Universidade de Santiago de Compostela. Departamento de Física Aplicada; Universidade de Santiago de Compostela. Departamento de Química Física; Universidade de Santiago de Compostela. Instituto de Materiais (iMATUS)
Coating synthetic nanoparticles (NPs) with lipid membranes is a promising approach to enhance the performance of nanomaterials in various biological applications, including therapeutic delivery to target organs. Current methods for achieving this coating often rely on bulk approaches which can result in low efficiency and poor reproducibility. Continuous processes coupled with quality control represent an attractive strategy to manufacture products with consistent attributes and high yields. Here, this concept is implemented by developing an acoustic microfluidic device together with an analytical platform to prepare nanoparticle-vesicle hybrids and quantitatively characterize the nanoparticle coverage using fluorescence-based techniques at different levels of resolution. With this approach polymethyl methacrylate (PMMA) nanoparticles are successfully coated with liposomes and extracellular vesicles (EVs), achieving a high encapsulation efficiency of 70%. Moreover, the approach enables the identification of design rules to control the efficiency of encapsulation by tuning various operational parameters and material properties, including buffer composition, nanoparticle/vesicle ratio, and vesicle rigidity.
Geometry-Driven Field-Induced Single-Ion Magnetism in Hexagonal Bipyramidal Tb3+ and Ho3+ Complexes
(American Chemical Society, 2025-10-11) González Barreira, Cristina; Oreiro Martínez, Paula; Fondo Busto, María Matilde; Corredoira Vázquez, Julio; García Deibe, Ana María; Sanmartín Matalobos, Jesús; Aravena, Daniel; Colacio, Enrique; Universidade de Santiago de Compostela. Departamento de Química Inorgánica; Universidade de Santiago de Compostela. Instituto de Materiais (iMATUS)
The synthesis of the precursors [Ln(LN6en)(CH3COO)2](BPh4)·nH2O (Ln = Tb, n = 0, 1; Ln = Ho, n = 1, 2·H2O), followed by a ligand exchange reaction with triphenylsilanolate, results in the isolation of the complexes {[Ln(LN6en)(OSiPh3)2](BPh4)}·2CH2Cl2 (Ln = Tb, 3·2CH2Cl2; Ln = Ho, 4·2CH2Cl2). Single-crystal X-ray diffraction studies of 3·2CH2Cl2 and 4·2CH2Cl2 revealed that both compounds adopt a hexagonal bipyramidal geometry. Magnetic characterization shows that the complexes behave as single-ion magnets (SIMs) under an optimal applied field of 2000 Oe. Notable, these are the first reported Tb3+ and Ho3+ complexes with a hexagonal bipyramidal coordination geometry to exhibit such magnet-like behavior. Furthermore, they constitute the first field-induced Tb3+ and Ho3+ SIMs incorporating a macrocyclic ligand in a nonsandwich topology. Magnetic measurements indicate that the applied field only partially suppresses quantum tunneling of magnetization (QTM) and that at higher temperatures magnetic relaxation is dominated by the Raman process rather than the Orbach mechanism. These experimental observations are supported by ab initio calculations, which provide detailed insights into the electronic structure, including the splitting of f-orbital energy levels, thereby elucidating the origin of the observed magnetic behavior in both cases
Bioaccumulation patterns in aquaculture mussels and turbots exposed to different sizes of TiO2NPs
(Elsevier, 2025-12-17) López Mayán, Juan José; Peña Vázquez, Elena María; Moreda Piñeiro, Antonio; Bermejo Barrera, Pilar; Maguire, Julie A.; Mackey, Mick; Vázquez, María; Mallo, Natalia; Cabaleiro, Santiago; Barciela Alonso, María Carmen; Universidade de Santiago de Compostela. Departamento de Química Analítica, Nutrición e Bromatoloxía; Universidade de Santiago de Compostela. Instituto de Materiais (iMATUS)
Titanium dioxide nanoparticles (TiO2NPs) are widely used in industry, leading to their presence in the marine environment where they can interact with and harm marine life. This study examines the impact and bioaccumulation of TiO2NPs in aquaculture mussels and turbot species. Mussels were exposed for 28 days, and turbot for 90 days, to different concentrations of citrate-coated TiO2NPs (25 and 5 nm). Inductively coupled plasma mass spectrometry (ICP-MS) and single-particle-ICP-MS (SP-ICP-MS) were used for Ti determination, and TiO2NPs content and size distribution determination. In mussels TiO2NPs concentrations reached 2.28 × 10^8±5.84 × 10^7 NPs g^−1 after exposure to 1.0 mg L^−1 of 25 nm TiO2NPs for 28 days, and 4.79 × 10^8±2.36 × 10^8 NPs g^−1 for 1.0 mg L^−1 of 5 nm TiO2NPs at 21 days, respectively. Bioaccumulation was also observed in mussel shells, which became fragile, with the highest Ti concentration reaching 12.4 ± 3.5 µg g^−1 d.w. In turbot, the highest Ti concentration was found in the liver, reaching 1.6 ± 0.4 µg g^−1 w.w. at 90 days to the highest dose of 5 nm TiO2NPs. Furthermore, turbots expelled Ti through the feces, reaching 41.0 ± 6.6 µg g^−1 d.w. The results show the safety of turbot consumption and highlight the need for a correct depuration process of mussels before commercialization.

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